1. Orgasm-associated urinary incontinence (climacturia) following radical prostatectomy: A review of pathophysiology and current treatment options
Asian Journal of Andrology 2020;22(6):549-554
Orgasm-associated urinary incontinence, or climacturia, is a common side effect after radical prostatectomy (RP) that is gaining more attention due to the distress it causes to patients. A range of treatment options have been reported in the literature and are outlined in this review. The goal of our study is to review the pathophysiology and current management options for climacturia following RP. A PubMed search was used to review the current literature relating to the pathophysiology and the treatment of postprostatectomy climacturia. We reviewed the currently available treatment options and their success rates for climacturia. Several techniques were found to subjectively help improve the amount and bother of patients' climacturia. These include pelvic floor muscle training (PFMT), penile variable tension loop, soft silicone occlusion loop, artificial urethral sphincter, male urethral sling, and the Mini-Jupette graft. Success rates ranged from 48% to 100% depending on the modality used. For patients with erectile dysfunction and climacturia, the Mini-Jupette graft could be a valuable option. Given the lack of validated measurement tools and management options, climacturia has become a challenge for urologists. Albeit a condition that has not garnered much attention, there are several management options from conservative to invasive treatments that have shown a hopeful promise for the treatment of climacturia. These options should be discussed with patients to determine the best treatment for each individual. More clinical trials are needed to assess the efficacy and impact of the different treatment options before a definitive recommendation regarding management can be made.
2. Sperm retrieval success and testicular histopathology in idiopathic nonobstructive azoospermia
Asian Journal of Andrology 2020;22(6):555-559
Prior studies have investigated sperm retrieval rates in men with nonobstructive azoospermia (NOA) secondary to specific etiologies, yet most cases of NOA are idiopathic. We compared sperm retrieval rates and testicular histopathology in idiopathic NOA (iNOA) and nonidiopathic NOA (niNOA). We performed a retrospective review of men with NOA who underwent microdissection testicular sperm extraction (microTESE) between 2000 and 2016. Men with no history of malignancy or cryptorchidism and negative genetic evaluation were considered idiopathic. Multivariable regression determined the association between idiopathic etiology and primary outcomes of sperm retrieval and active spermatogenesis on histopathology. Among 224 men, 86 (38.4%) were idiopathic, 75 (33.5%) were nonidiopathic, and 63 (28.1%) did not undergo genetic testing. Median age and serum testosterone were higher among iNOA or no testing versus niNOA. Median follicle-stimulating hormone (FSH) was lower among iNOA or no testing versus niNOA. A higher proportion of iNOA or no testing versus niNOA had a clinical varicocele. Sperm retrieval rates were similar between iNOA, niNOA, and no testing (41.8% vs 48.0% vs 55.6%, respectively; P = 0.255). Active spermatogenesis was seen in a higher proportion of iNOA or no testing versus niNOA (31.4% and 27.0% vs 16.0%, P = 0.073). On multivariaile analysis, iNOA was not associated with sperm retrieval or spermatogenesis (P = 0.430 and P = 0.078, respectively). Rates of sperm retrieval and spermatogenesis on testis pathology were similar in men with iNOA and niNOA. These data will be useful to clinicians in preoperative counseling for men with NOA and negative genetic evaluation.
3. Metformin treatment of high-fat diet-fed obese male mice restores sperm function and fetal growth, without requiring weight loss
Asian Journal of Andrology 2020;22(6):560-568
Male obesity is associated with subfertility and increased disease risk of offspring. It is unknown if effects can be reversed through pharmacological interventions. Five- to 6-week-old C57BL6 male mice were fed control diet (n = 10, CD) or high-fat diet (n = 20, HFD) for 16 weeks. Animals fed with a HFD were then allocated to continuation of HFD (n = 8) or HFD with metformin 28 mg kg-1day-1(n = 8) for 6 weeks. Animals fed with CD continued on a CD (n = 9). Males were mated with fertile C57BL6 females for the assessment of pregnancy and fetal growth. Sperm motility, spermatozoa and testicular morphology, sperm-zona pellucida binding, sperm reactive oxygen species (ROS) (intracellular [DCFDA], superoxide [MSR], and oxidative DNA lesions [8OHdG]), and mitochondrial membrane potential (JC1) were assessed. Metformin treatment of HFD males improved glucose tolerance (+12%, P < 0.05) and reduced Homeostatic Model Assessment of Insulin Resistance (HOMA-IR; -36%, P < 0.05). This occurred in the absence of a change in body weight or adiposity. Metformin treatment of HFD-fed males restored testicular morphology (+33%, P < 0.05), sperm motility (+66%, P < 0.05), sperm-zona pellucida binding (+25%, P < 0.05), sperm intracellular ROS concentrations (-32%, P < 0.05), and oxidative DNA lesions (-45%, P < 0.05) to the levels of the CD males. Metformin treatment of HFD fathers increased fetal weights and lengths compared with those born to HFD fathers (+8%, P < 0.05), with fetal lengths restored to those of fetuses of CD males. Short-term metformin treatment in men who are obese could be a potential intervention for the treatment of subfertility, without the need for a reduction in body weight/adiposity. McPherson Nicole 1 , Lane Michelle 2 , ABS, Australian Bureau of Statistics. Gender Indicators, Australia Sep 2018. 2018; Vol 4.
4. Identification of sumoylated targets in proliferating mouse spermatogonia and human testicular seminomas
Asian Journal of Andrology 2020;22(6):569-577
Spermatogenesis is regulated by a complex network of posttranslation modifications. Sumoylation (a modification by small ubiquitin-like modifiers, or SUMO proteins) was identified as an important cellular event in different cell types. SUMO proteins are highly expressed in the testis, and their role during spermatogenesis has begun to be elucidated. Given the important role of sumoylation in the regulation of mitosis and cancer progression in other tissues, the aim of the current study was to identify the targets of SUMO in proliferating mouse spermatogonia and human seminoma tissues and to initially examine the level of sumoylation in relation to the proliferative activity of the tissues. Using freshly purified spermatogonia and C18-4 spermatogonia cell line, mass spectrometry analysis identified several SUMO targets implicated into the proliferation of spermatogonia (such as heat shock protein 60 [HSP60] and prohibitin). Tissue array and western blot approaches showed that SUMO expression is a prominent feature of human seminomas and that the proliferative activity of the tumor tissues was positively correlated with the level of SUMO expression. Downregulation of sumoylation with si-RNA was not sufficient to significantly affect the proliferation of C18-4 spermatogonia; however, SUMO overexpression increased the proliferation rate of the cells. These data suggest that cells are more sensitive to an elevated level of SUMO, and that this situation may lead to an upregulated cellular proliferation and, possibly, cancer. Mass spectrometry analysis identified around a hundred SUMO targets in seminoma samples. Notably, many of the identified proteins (such as proliferating cell nuclear antigen [PCNA], DNA topoisomerase 2-alpha [Top2A], prohibitin, 14-3-3 protein, and others) were implicated in oncogenic transformation and cancer progression.
5. Relationship of sperm plasma membrane and acrosomal integrities with sperm morphometry in Bos taurus
Asian Journal of Andrology 2020;22(6):578-582
To date, sperm morphometric studies have assessed whole sperm populations without considering sperm function. The aim of this study was to evaluate the relationship of sperm membrane and acrosomal integrity with sperm morphometry in liquid semen samples collected from bulls. To this end, sperm morphometry was performed on cryopreserved semen samples from 16 bulls by a combination of fluorescent dyes, including Hoechst 33343, carboxyfluorescein diacetate, and propidium iodide. This allowed discrimination of different subpopulations on the basis of sperm membrane and acrosomal integrity and analysis of the morphometrics of the sperm head, nucleus, and acrosome using a specific plug-in module created on ImageJ. Acrosomal integrity was related to sperm morphometry as the heads of spermatozoa with a damaged acrosome were significantly smaller than those with a normal acrosome (P < 0.001). In the case of spermatozoa with an intact acrosome, those with a damaged plasma membrane had a larger sperm head and acrosome than spermatozoa with an intact plasma membrane (P < 0.001). No significant differences in the sperm head size were observed between sperm subpopulations without an acrosome or in the nuclear sperm morphometry of the different subpopulations. There was a positive correlation between the sperm motility values of the samples and the morphometric parameters for intact spermatozoa. These correlations were particularly strong for the morphometric parameters of the sperm acrosome. We conclude that there are clear differences in the sperm morphometry depending on the status of the sperm membrane and acrosome and this should be considered when performing this kind of analysis.
6. Prohibitin (PHB) interacts with AKT in mitochondria to coordinately modulate sperm motility
Asian Journal of Andrology 2020;22(6):583-589
Prohibitin (PHB), an evolutionarily conserved mitochondrial inner membrane protein, is highly expressed in cells that require strong mitochondrial function. Recently, we demonstrated that the deletion of Phb in spermatocytes results in impaired mitochondrial function. In addition, PHB expression in the mitochondrial sheath of human sperm has a significantly negative correlation with mitochondrial reactive oxygen species levels, but a positive one with mitochondrial membrane potential and sperm motility. These results suggest that mitochondrial PHB expression plays a role in sperm motility. However, the mechanism of PHB-mediated regulation of sperm motility remains unknown. Here, we demonstrate for the first time that PHB interacts with protein kinase B (AKT) and exists in a complex with phospho-PHB (pT258) and phospho-AKT in the mitochondrial sheath of murine sperm, as determined using colocalization and coimmunoprecipitation assays. After blocking AKT activity using wortmannin (a phosphatidylinositol 3-kinase [PI3K] inhibitor), murine sperm have significantly ( P < 0.05) decreased levels of phospho-PHB (pT258) and the total and progressive motility. Furthermore, significantly ( P < 0.05) lower levels of phospho-PI3K P85 subunit α+γ (pY199 and pY467) and phospho-AKT (pS473; pT308) are found in sperm from infertile asthenospermic and oligoasthenospermic men compared with normospermic subjects, which suggest a reduced activity of the PI3K/AKT pathway in these infertile subjects. Importantly, these sperm from infertile subjects also have a significantly ( P < 0.05) lower level of phospho-PHB (pT258). Collectively, our findings suggest that the interaction of PHB with AKT in the mitochondrial sheath is critical for sperm motility, where PHB phosphorylation (pT258) level and PI3K/AKT activity are key regulatory factors.
7. Knockout of glutathione peroxidase 5 down-regulates the piRNAs in the caput epididymidis of aged mice
Asian Journal of Andrology 2020;22(6):590-601
The mammalian epididymis not only plays a fundamental role in the maturation of spermatozoa, but also provides protection against various stressors. The foremost among these is the threat posed by oxidative stress, which arises from an imbalance in reactive oxygen species and can elicit damage to cellular lipids, proteins, and nucleic acids. In mice, the risk of oxidative damage to spermatozoa is mitigated through the expression and secretion of glutathione peroxidase 5 (GPX5) as a major luminal scavenger in the proximal caput epididymidal segment. Accordingly, the loss of GPX5-mediated protection leads to impaired DNA integrity in the spermatozoa of aged Gpx5-/-mice. To explore the underlying mechanism, we have conducted transcriptomic analysis of caput epididymidal epithelial cells from aged (13 months old) Gpx5-/-mice. This analysis revealed the dysregulation of several thousand epididymal mRNA transcripts, including the downregulation of a subgroup of piRNA pathway genes, in aged Gpx5-/-mice. In agreement with these findings, we also observed the loss of piRNAs, which potentially bind to the P-element-induced wimpy testis (PIWI)-like proteins PIWIL1 and PIWIL2. The absence of these piRNAs was correlated with the elevated mRNA levels of their putative gene targets in the caput epididymidis of Gpx5-/-mice. Importantly, the oxidative stress response genes tend to have more targeting piRNAs, and many of them were among the top increased genes upon the loss of GPX5. Taken together, our findings suggest the existence of a previously uncharacterized somatic piRNA pathway in the mammalian epididymis and its possible involvement in the aging and oxidative stress-mediated responses.
8. Prognostic value of primary tumor surgery in seminoma patients with distant metastasis at diagnosis: A population-based study
Asian Journal of Andrology 2020;22(6):602-607
The aims of this study were to determine the prognostic value of primary tumor surgery and identify optimal candidates for such surgery among patients with seminoma and distant metastasis at diagnosis. We identified 521 patients with seminoma and distant metastasis at diagnosis between 2004 and 2014 from the Surveillance, Epidemiology, and End Results database. Among these patients, 434 had undergone surgery, whereas 87 had not. The prognostic value of primary tumor surgery was assessed by Kaplan-Meier methods, log-rank analyses, and multivariate Cox's proportional hazards model. Survival curves and forest plots were also plotted. Survival analysis indicated that patients who underwent surgery had a better 5-year overall survival and cancer-specific survival than those who did not. Multivariate analyses demonstrated that primary tumor surgery is an independent prognostic factor for overall survival and cancer-specific survival, along with age at diagnosis, M stage, and marital status. In addition, primary tumor surgery still had considerable prognostic value in the subgroup of patients with lymph node metastasis. Further, forest plots demonstrated that patients with M1a stage, N1 or N2-3 stage, and a younger age at diagnosis (<60 years) may benefit from primary tumor surgery. In conclusion, our findings indicate that primary tumor surgery is correlated with improved survival in patients with seminoma and distant metastasis.
9. Gene transcription profiling of astheno- And normo-zoospermic sperm subpopulations
Asian Journal of Andrology 2020;22(6):608-615
Spermatozoa contain a repertoire of RNAs considered to be potential functional fertility biomarkers. In this study, the gene expression of human sperm subpopulations with high (F1) and low (F2) motility from healthy normozoospermic (N) and asthenozoospermic (A) individuals was evaluated using RNA microarray followed by functional genomic analysis of differentially expressed genes. Results from A-F1 versus N-F1, A-F2 versus N-F2, N-F1 versus N-F2, and A-F1 versus A-F2 comparisons showed a considerably larger set of downregulated genes in tests versus controls. Gene ontology (GO) analysis of A-F1 versus N-F1 identified 507 overrepresented biological processes (BPs), several of which are associated with sperm physiology. In addition, gene set enrichment analysis of the same contrast showed 110 BPs, 36 cellular components, and 31 molecular functions, several of which are involved in sperm motility. A leading-edge analysis of selected GO terms resulted in several downregulated genes encoding to dyneins and kinesins, both related to sperm physiology. Furthermore, the predicted activation state of asthenozoospermia was increased, while fertility, cell movement of sperm, and gametogenesis were decreased. Interestingly, several downregulated genes characteristic of the canonical pathway protein ubiquitination were involved in asthenozoospermia activation. Conversely, GO analysis of A-F2 versus N-F2 did not identify overrepresented BPs, although the gene set enrichment analysis detected six enriched BPs, one cellular component, and two molecular functions. Overall, the results show differences in gene transcription between sperm subpopulations from asthenozoospermic and normozoospermic semen samples and allowed the identification of gene sets relevant to sperm physiology and reproduction.
10. MAGI-2 downregulation: A potential predictor of tumor progression and early recurrence in Han Chinese patients with prostate cancer
Asian Journal of Andrology 2020;22(6):616-622
Membrane-associated guanylate kinase (MAGUK) family protein MAGUK invert 2 (MAGI-2) has been demonstrated to be involved in the tumorigenic mechanism of prostate cancer. The objective of this study was to investigate the expression of MAGI-2 at mRNA and protein levels. The prognostic value of MAGI-2 in Han Chinese patients with prostate cancer was also investigated. The expression data of MAGI-2 were assessed through database retrieval, analysis of sequencing data from our group, and tissue immunohistochemistry using digital scoring system (H-score). The clinical, pathological, and follow-up data were collected. The expression of MAGI-2 in prostate tumor tissues and prostate normal tissues was evaluated and compared. MAGI-2 expression was associated with clinical parameters including tumor stage, lymph node status, Gleason score, PSA level, and biochemical recurrence of prostate cancer. The relative expression of MAGI-2 mRNA was lower in the tumor tissue in The Cancer Genome Atlas (TCGA) database and sequencing data (P < 0.001). There was no difference in MAGI-2 protein expression between tumor and normal tissues in tissue microarray (TMA) results. MAGI-2 expression was associated with pathological tumor stage (P = 0.02), Gleason score (P = 0.05), and preoperation prostate-specific antigen (PSA; P = 0.04). A positive correlation was identified between MAGI-2 and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expressions through the analysis of TCGA and TMA data (P < 0.0001). Patients with higher MAGI-2 expression had longer biochemical recurrence-free survival in the univariate analysis (P = 0.005), which indicates an optimal prognostic value of MAGI-2 in Han Chinese patients with prostate cancer. In conclusion, MAGI-2 expression gradually decreases with tumor progression, and can be used as a predictor of tumor recurrence in Chinese patients.